An experimental procedure known for detecting white corpuscles in the cerebrospinal liquid then consists of depositing, on a microscope slide, a droplet of about 10 μL of cerebrospinal liquid which has been sampled beforehand on the patient, the sampling step not being concerned by the present invention.
It is agreed that meningitis is diagnosed if a 10 μl sample of cerebrospinal liquid contains at least 10 white corpuscles, these white corpuscles being the indirect marking of a viral or bacterial infection.
However, the counting of these white corpuscles is a tedious operation for the technician and quite inaccurate, since the question is to count white corpuscles with a microscope. A more specific alternative, but much more expensive, long to be applied and requiring a cumbersome apparatus, consists of resorting to cytometry methods.